It is December 29, 1972, and Eastern Air Lines Flight 401 has just taken off from the bitter cold of New York City and is heading out to Miami. One hundred and sixty-three passengers are on board, most of them hoping to enjoy a New Year’s vacation in the sun.
The flight is smooth and without incident as, a little before midnight, the plane makes its final approach into Miami International Airport. The wheels are lowered in preparation for landing, the captain informs the guests of the local temperature, and the passengers fasten their seat belts.
But then the captain notices that something is wrong. On most aircraft, there are three sets of wheels: one set beneath each of the two wings, and another just below the nose. When the wheels are lowered into place and lock into position for landing, indicators in the cockpit light up. But the green light linked to the wheels beneath the nose has failed to illuminate.
This could mean one of two things: either the light itself is faulty or the wheels have failed to lock into place. Either way, the captain has no choice but to abort his landing to figure out what has gone wrong. He informs air traffic control at just after half past eleven.
What happens next will ultimately cause one of the biggest civil aviation disasters in history. The crew members fixate on the faulty light. They pull it from its fitting, they turn it around in their hands, they blow on it to remove dust, they get it jammed when trying to put it back in its fitting. They devote so much attention to the light, they fail to notice the gorilla in their midst.
The gorilla, in this case, is the fact that the autopilot has been inadvertently disengaged, and the airplane is losing altitude. As the crew continue to focus their attention on the light, the plane is now taking the crew and passengers on a downward path toward disaster in the Everglades.
As the plane drops through 1,750 feet, an altitude warning alarm rings through the cockpit. The alarm is part of a sophisticated warning system, informing the pilots of their mortal danger. But although the alarm is clearly audible on the black box recording, neither the pilot nor the copilot hears it. Their attention is so wrapped up with the light, they have no spare bandwidth with which to consciously register the noise. They are now less than one hundred seconds from death.
Altitude is declining every second. The pilots can’t feel it because their senses are deceived by the plane’s motion. They can’t see it through the windows because it’s a moonless night, and there is no visible horizon. But right in front of the pilot’s noses, the altitude meter is spinning downward. It is within their line of sight. It is possible that both pilot and copilot actually look at the meter and see it moving. But they can’t perceive what it is saying. Why? Because it never hits conscious awareness.
Only when the plane is seven seconds from impact with the ground does the copilot finally realize that something is seriously wrong. The pilot takes evasive action, pulling hard on the lever, but it’s too late. A moment later the plane crashes, killing 101 people.
attentional resources vs. insufficient bandwidth
Perhaps the most remarkable thing about Eastern Air Lines Flight 401 is that the plane’s detailed warning systems worked. The altitude meter told the pilots that the plane was descending, and the alarm system provided the same information in acoustic form. But neither made the slightest bit of difference. The pilots had insufficient bandwidth. They were inattentionally blind. For the pilots, focused on the faulty light, it was as if the warnings never happened. They vanished into the realms of the unconscious.
Crash investigators would later establish that the nose wheels had, in fact, locked into place: the plane could have landed. The only piece of faulty equipment was the lightbulb in the nose gear assembly fixture, which had burned out. One journalist said, “The crash occurred due to the failure of a $12 piece of kit.” In a way, he was right, but the deeper truth is that a warning system, however sophisticated, is often only as good as the attentional resources at the disposal of the crew.
Eastern Air Lines Flight 401 has become a seminal event in aviation safety history, changing the way crashes are investigated and the way pilots are trained. A key innovation in crew training systems is a clear procedure of delegation between the pilot and the copilots in order to free up attentional resources.
The problem with the faulty lightbulb was not just that the captain fixated on it, but that the rest of the crew did, too: the pool of attention was exclusively focused on a single problem. Had just one of the crew focused on the light fitting, there would have been plenty of available attention for the others to have picked up on the visual and acoustic cues indicating the plane’s descent.
- Matthew Syed, Bounce: Mozart, Federer, Picasso, Beckham, and the Science of Success, Chapter 8
